Side Airbag Deflector Serpentine Flow Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Side airbags in vehicles often deploy too rapidly, leading to insufficient retention of inflation pressure, which can result in inadequate protection for occupants during side impacts.
Innovation Solution
A deflector is integrated into the side airbag design to deflect and delay the discharge of inflation gas, maintaining internal pressure by creating a back-pressure through a serpentine flow path that directs gas flow around the vent, ensuring the airbag remains inflated longer and effectively positions the occupant's arm to prevent trapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a simple opening vent is used for rapid gas discharge, then the airbag can empty quickly, but the internal pressure is lost too rapidly and the airbag cannot maintain inflation long enough
Solution Approach 1:
The vent is divided into multiple separate openings distributed around the airbag periphery instead of a single large opening. This segmentation allows gas to discharge through multiple paths simultaneously, maintaining higher internal pressure for longer duration while still achieving rapid overall discharge. The segmented vent structure resolves the contradiction by enabling both fast discharge and pressure retention.
Solution Approach 2:
The vent openings are positioned at the periphery of the airbag rather than centrally, utilizing the peripheral dimension for gas discharge. This dimensional change allows the main body of the airbag to maintain pressure while gas escapes through distributed peripheral openings, extending inflation duration despite rapid discharge capability.
2Productivity
If gas is discharged rapidly from the airbag, then the venting function is achieved, but the protection effectiveness is reduced due to insufficient pressure retention
Solution Approach 1:
The vent is segmented into multiple small openings distributed around the airbag periphery. This segmentation enables efficient gas discharge through multiple parallel paths while maintaining higher internal pressure for longer, thus ensuring reliable occupant protection throughout the critical time period.
Solution Approach 2:
The vent opening parameters are changed from a single large opening to multiple small peripheral openings. This parameter change optimizes the balance between discharge efficiency and pressure retention, ensuring both high productivity in gas discharge and high reliability in occupant protection.
3Duration of action of moving object
If the airbag inflates rapidly to protect the occupant, then immediate protection is provided, but the gas pressure is not retained sufficiently long to maintain effective protection
Solution Approach 1:
The peripheral segmented vent structure allows the airbag to inflate rapidly while retaining internal pressure for extended duration. The multiple small openings provide sufficient discharge capability without compromising pressure retention, thus extending the effective protection duration while maintaining adequate internal pressure.
Solution Approach 2:
The segmented vent design ensures continuous gas discharge throughout the inflation period, maintaining pressure equilibrium. This continuous action allows the airbag to remain inflated at effective pressure levels for longer duration, extending the useful protection period.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively maintains airbag inflation longer, reducing the risk of occupant injury by ensuring the airbag remains inflated and positioning the arm to avoid being trapped between the airbag and the thorax during side impacts.
Implementation Method 1
A deflector is provided for the deflection and delayed discharge of the gas from the airbag, said deflector blocking the flow of inflation gas to the airbag's exterior vent
Implementation Method 2
The deflector may be designed and arranged so that the gas flow is initially guided past and preferably away from the vent before being allowed to reach the vent. A delay in the gas flow may be achieved by creating a back-pressure, whereby the internal pressure is maintained longer upstream of the deflector
Data Source
AI summary
A side airbag for protection for vehicle occupants includes an interior wall separating the airbag into upstream and downstream chambers and defining an opening between two chambers adjacent a lower end of the airbag. A flow deflector between the opening and an exterior vent combines with the wall to define a channel therebetween. The channel directs inflation gasses exiting the opening into an upper end of the airbag, after which the gasses must flow around an upper end of the deflector (adjacent an outlet end of the channel) before reaching the exterior vent. The resulting S-shaped flow path serves to maintain the airbag in the inflated state for a longer time and urges an outboard arm of an occupant in a forward an upward direction to reduce the likelihood that that arm may be trapped between the inflating airbag and the occupant's thorax.